Hauling vehicle

ABSTRACT

A hauling vehicle in the form of a so-called terminal tractor intended for transporting containers, but which also can be used for transporting different kinds of trailers provided only with rear wheels, is two-axled and provided at its rear end with connecting means designed to provide essentially rigid interconnection of the vehicle frame with the front end of the container or trailer to be hauled. The rear wheels of the hauling vehicle are steerable as well as drivable from the driving motor of the vehicle. The rear axle is connected to the vehicle frame by means, e.g., hydraulic cylinders, enabling adjustment of the vertical position of the vehicle frame relative to the rear axle. After the rear end of the vehicle frame has been rigidly interconnected with the front end of the container, the vehicle frame can be raised relative to the rear axle, whereby the front end of the container is lifted up into the air. The distribution of the weight of the vehicle between its rear axle and its front axle is such that the front wheels of the vehicle are lifted up into the air. If the rear end of the container has been provided with a temporarily affixed wheel set, the hauling vehicle together with the container will form a drivable equipage whose drivable and steerable front wheels are the rear wheels of the hauling vehicle.

The present invention relates to a hauling vehicle which particularly isintended for transporting containers but which also can be adapted to beused for many other purposes e.g. for transporting different kinds oftrailers.

At harbours, airports, railroad stations, and all other kinds of goodsstations there is a great need for simple and efficient devices fortransporting containers which can have very large dimensions and largeweight, e.g. a length of about 12 meters and a weight of about 30 tons.This transportation is to be carried out quickly, smoothly and withgreat accuracy also in narrow spaces as e.g. when loading and unloadingships.

A problem which to some extent is similar exists concerning trailerswhich are designed to be connected to separate hauling vehicles providedwith a turntable but which upon transportation by means of ships are notaccompanied by their associated hauling vehicles but have to be hauledby other auxiliary means upon loading and unloading as in general alsoupon other kinds of station transportation. For this purpose it is knownto use short two-axled tractor-like hauling vehicles provided with aturntable lifting device so that they can be connected to trailers fortransporting them shorter distances and with moderate velocity.

Of course, the same method can not quite easily be applied to theloading and unloading and other kinds of terminal transportation ofcontainers which as we all known do not have any wheels of their own. Ina known system for loading and unloading containers on ships as well asfor other kinds of terminal transportation the containers are thereforeplaced on very low open-sided wagons, so called roll trailers, which areprovided with wheels or rolls only at one end while the other end of thewagon is designed to be connected to and carried by the turntablelifting device on a terminal tractor of the above kind by means of a socalled swan-neck. Thus, the wagon and the container located thereon canbe hauled by said tractor. However, such extra roll trailers forcontainers lead to an essentially increased capital cost for thetransport system since the trailers have to accompany the containersduring the whole transport on board the ship as well as to extrahandling costs for loading and unloading the containers on these rolltrailers.

For transporting containers it is, therefore, also known to use loosesets of wheels or rolling means which can be attached to the lowercorner mountings on the container resting on an underlayer, and whichhave wheels which can be lowered by means of hydraulic cylinders or thelike so that the container by lowering of the wheels can be lifted fromthe underlayer to a transport position in which the container can behauled by a hauling vehicle which in a suitable manner is connected tothe rolling means at one end of the container. However, these rollingmeans have to be designed in a special way in order to be connected to ahauling vehicle.

The hitherto known systems for transporting containers whether these areprovided with temporarily affixed rolling means or located on lowopen-sided wagons, so called roll trailers, are, however, impaired byserious disadvantages, particularly in the form of bad manoeuvrabilityupon transportation in narrow spaces, e.g. on ships, due to largeturning radii. The known systems are also in many cases comperativelycomplicated and time-consuming to use and often so specialized that theycannot be used for transportation of containers provided with separatelyaffixed rolling means as well as containers placed on so called rolltrailers.

The object of the present invention is therefore to provide a haulingvehicle which above all can be used for transporting containers andwhich gives a very good manoeuvrability and which, moreover, very easilycan be adapted to be used for transporting containers provided withseparately affixed rolling means as well as containers located on socalled roll trailers and for hauling trailers designed for connection tohauling vehicles provided with a turntable lifting device andprincipally for hauling any trailer provided with wheels only at itsrear part.

The hauling vehicle according to the invention has front wheels and rearwheels suspended from a frame, and connecting means at the rear end ofthe vehicle for connecting the vehicle to an object to be hauled, and ismainly characterized in that said connecting means are attached to theframe of the vehicle and designed to provide a substantially rigidinterconnection between the frame of the vehicle and the object to behauled, that means are provided for adjusting the vertical position ofthe vehicle frame relative to the rear wheels, that these rear wheelsare steerably and drivably connected to the driving means of the vehicleand that the distribution of the weight of the vehicle on the frontwheels and the rear wheels, respectively, is so adapted to the weight ofthe object to be hauled that after interconnecting the vehicle and theobject by means of said connecting means the front wheels can be liftedup by raising the vehicle frame relative to the rear wheels.

A hauling vehicle designed in accordance with the invention can veryeasily and quickly be connected to and disconnected from, respectively,the object to be hauled whether this is a container, a so called rolltrailer loaded with containers, a conventional trailer for connection toa turntable or any other type of trailer. The equipage then obtained hasas short a wheel base as the design of the hauled object on the wholeallows and the steerable wheels of the equipage are located very closeto the front end of the hauled object, e.g. the container, which makesthe equipage very easy to manoeuvre also in narrow spaces. It is alsoeasy to design the hauling vehicle according to the invention in such amanner that the steerable wheels of the equipage can be turned withinvery large steering angles up to almost ±90° which further increases themanoeuvrability. When the hauling vehicle according to the invention isdriven without being connected to any hauled object, the vehicle is aseasy to manoeuvre as any conventional terminal tractor.

The invention will be described more in detail below with reference tothe attached drawings on which

FIG. 1 is a schematical sideview of an embodiment of a vehicle accordingto the invention designed mainly for transporting containers,

FIG. 2 shows the vehicle according to FIG. 1 from the front,

FIG. 3 shows the vehicle according to FIG. 1 from above,

FIG. 4 schematically shows a section along the line IV--IV in FIG. 1through the rear axle system of the vehicle,

FIG. 5 is a schematical sideview showing how a hauling vehicle offundamentally the design shown in FIGS. 1-4, is connected to a containerresting directly on the ground or something equivalent,

FIG. 6 is a sideview corresponding to FIG. 5 but showing the equipage inraised transport position,

FIG. 7 is a schematical sideview illustrating how a hauling vehicleaccording to the invention can be used for transporting conventionaltrailers designed for connection to a turntable,

FIG. 8 is a schematical sideview illustrating how a hauling vehicleaccording to the invention can be used for transporting a first type oflow-loading trailers, so called roll trailers, for containers,

FIG. 9 is a schematical sideview illustrating how a hauling vehicleaccording to the invention can be used for transporting a type of rolltrailer which is intended to be connected via a swan-neck device to ahauling vehicle provided with a turntable lifting device, and

FIG. 10 is a schematical sideview illustrating how a hauling vehicleaccording to the invention can be provided with a goods-handling fork tobe used in the same manner as a fork truck.

The embodiment of the hauling vehicle according to the invention, shownschematically in FIGS. 1-4, is first of all intended and designed fortransporting containers as will be described more in detail withreference to FIGS. 5 and 6. The vehicle has a rigid frame 1 whichcarries a driver's cab 2 and a driving motor unit 3 (not shown indetail). The vehicle is two-axled with a front axle 4 with associatedfront wheels 5 and a rear axle 6 with associated rear wheels 7. At therear end of the vehicle frame 1 there is a connecting device 8 affixedto the frame for connecting the vehicle to the object to be hauled ortransported i.e. preferably a container in the embodiment shown. Theconnecting device 8 should be designed to provide an essentially rigidinterconnection between the vehicle frame 1 and the object to be hauledor transported, and comprises in the shown embodiment an essentiallyvertical rectangular frame which has the same dimensions as thegable-end of the containers to be transported by the hauling vehicle,and which at its corners are provided with suitably designed and in theshown embodiment hydraulically operable locking means 9 which can bebrought into engagement with corner mountings at the gable-end of acontainer so that the connecting frame 8 and, thereby, the vehicle frame1 is interconnected with the container as will be described more indetail with reference to FIGS. 5 and 6.

As opposed to what normally is the case in vehicles the front axle 4with the front wheels is rigidly, i.e. not steerably, united with thevehicle frame 1. That the front axle 4 with the front wheels 5 is"rigidly" united with the vehicle frame 1 does, of course, not excludethat there are suitable spring means between the vehicle frame 1 and thefront axle 4. Neither are the front wheels 5 drivable from the drivingmotor unit 3 of the vehicle.

The rear wheels 7 on the rear axle 6 are, however, drivable from thedriving motor unit 3 as well as steerable, and, moreover, the rear axle6 with the rear wheels 7 is connected to the vehicle frame 1 by means ofpower producing means which enable an adjustment of the verticalposition of the vehicle frame 1 relative to the rear axle 6 with therear wheels 7.

In the embodiment of the vehicle according to the invention shown on thedrawing this is accomplished in the manner schematically illustrated inFIG. 4 in that the rear wheels 7 are directly mounted on hydraulicmotors 10 arranged on the rear axle 6 which in turn is suspended fromthe vehicle frame 1 by means of an articulated leg 11 (compare FIG. 1)and a hydraulic cylinder 12 by means of which the distance between thevehicle frame 1 and the rear axle 6, thus, can be adjusted. Thehydraulic motors 10 for driving the rear wheels 7 are in a manner knownper se connected to a suitably designed hydraulic pump known per se withassociated control equipment included within the driving motor unit 3 ofthe vehicle. The whole rear axle system with the articulated leg 11, thehydraulic cylinder 12, the axle 6, the driving motors 10 and the wheels7 can for steering the vehicle be turned about a vertical axis in thatthe articulated leg 11 is rotatably mounted in the vehicle frame 1 andconnected to a suitable preferably hydraulic steering mechanism 13. Bythis design of the rear axle system it is attained that the steeringwheels 7 of the vehicle can be turned within a very large steeringangle, up to about ±90°, which makes the vehicle very easy to manoeuvrealso in narrow spaces.

FIGS. 5 and 6 illustrate how a hauling vehicle according to theinvention can be used for transporting a container. FIG. 5 shows acontainer 14 resting directly on a support i.e. in the position that thecontainer assumes upon connection and disconnection, respectively, ofthe hauling vehicle according to the invention. For connecting thehauling vehicle it is moved backwards to such a position at onegable-end of the container 14 that the connecting means 9 on theconnecting frame 8 at the rear end of the vehicle frame 1 can be lockedto the corner mountings on the gable-end of the container 14 so that anessentially rigid interconnection is obtained between the container 14and the vehicle frame 1. Since the distance between the vehicle frame 1and the rear axle 6 of the vehicle can be adjusted in the mannerdescribed above, the connecting frame 8 can be lowered far enough forinterconnection with the container 14. In the embodiment shown, theconnecting frame 8 is shown rigidly united with the vehicle frame 1 forsake of simplicity. A certain limited pivotability for the connectingframe 8 relative to the vehicle frame 1, at first hand about ahorizontal axis, can, however, be suitable or even necessary forfacilitating the interconnection between the connecting frame 8 and thecontainer 14 by means of the connecting means 9. After that thisinterconnection has been accomplished the connecting frame 8 is suitablyrigidly locked to the vehicle frame 1.

Moreover, to the rear end of the container 14 suitable wheel or rollmeans 15 are connected, which can be of any previously known type andwhich are provided with hydraulically hinged wheels. The hydrauliccontrol means for these roll or wheel means 15 can advantageously besupplied with hydraulic fluid and be controlled from the hydraulicsystem of the hauling vehicle in that the roll means 15 are connected toa hydraulic hose 16 which is removable from a hose reel 17 on thehauling vehicle.

After that the hauling vehicle according to the invention has beenconnected to one gable-end of the container 14 and the roll means 15locked to the other gable-end of the container 14 the vehicle frame 1 israised in the above described manner relative to the vehicle rear axle 6and the rear wheels 7 at the same time as the wheels of the roll means15 are lowered in a manner known per se. Hereby the container 14 will belifted from the support to the transport position schematically shown inFIG. 6 together with the vehicle frame 1 interconnected with thecontainer 14. This means that also the vehicle front axle 4 with thefront wheels 5 is lifted up from the support and an equipage isobtained, which have the rear axle 6 with the rear wheels 7 of thehauling vehicle as front axle with drivable and steerable front wheels,and the roll means 15 as non-steerable rear wheels. It is obvious thatthis equipage has a wheel base which is as short as practically possiblein view of the length of the container 14, and is very easy to manoeuvrealso in narrow spaces in that the steerable wheels 7 can be turnedwithin a very large steering angle and, moreover, are located very closeto the front end of the container 14.

It is also obvious that the connection and disconnection of the haulingvehicle from the container 14 can be carried out in a comparatively fastand simple manner. The only manual work required is to affix and remove,respectively, the roll means 15 at the rear end of the container 14.When transporting the hauling vehicle alone between different containersthe roll means 15 can be hung on the hauling vehicle.

Upon idle running of the hauling vehicle it is appreciated that thesteering takes place by means of the rear wheels of the vehicle, whileupon hauling a container the stearing of the thus formed equipage iscarried out with what in reality is the front wheels of the equipagewhich gives the opposite steering geometry for the equipage. Necessaryconsideration hereto can be taken by a reversal of the function of thesteering wheel in the driver's cab of the hauling vehicle so thatturning of the steering wheel in a certain direction always results inthe same change of direction for the travel of the vehicle independentof whether the vehicle is driven alone in the position shown in FIG. 1or interconnected with a container in the position shown in FIG. 6.

Since the front axle 4 and the front wheels 5 of the hauling vehicleonly are used when driving the vehicle alone, the front axle and thefront wheels do not have to be dimensioned for more than the tare weightof the hauling vehicle. The rear axle 6 and the rear wheels 7, however,have to be dimensioned with respect to the weight of the containers tobe hauled by means of the vehicle.

FIG. 7 schematically illustrates how a hauling vehicle according to theinvention can be used for hauling conventional trailers designed forconnection to hauling vehicles provided with a turntable. For thispurpose the connecting frame 8 of the hauling vehicle according to theinvention, generally denoted 18, is rigidly interconnected with thefront end of a short single-axled trailer 19 specially designed for thisinterconnection and which is provided with a turntable lifting device 20of conventional type for connecting the trailer 21 to be hauled andtransported. After having interconnected the hauling vehicle 18according to the invention with the trailer 19 the frame of the haulingvehicle is raised in the manner described above so that the front axle 4and the front wheels 5 of the hauling vehicle are lifted from thesupport and the equipage can be steered and driven by means of the rearwheels 7 of the hauling vehicle 18.

FIG. 8 schematically illustrates how the hauling vehicle 18 according tothe invention can be used for hauling and transporting a low-loadingroll trailer 22 which carries a container 14 or some other load. Thisroll trailer has a special front portion for interconnection with theconnecting frame 8 of the hauling vehicle.

In a corresponding manner FIG. 9 shows how a hauling vehicle 18according to the invention can be used for hauling and transporting alow-loading roll trailer 28 for e.g. containers 14, which roll trailerat its front end is provided with a connecting box 24 forinterconnection with a swan-neck device 25 which is rigidlyinterconnected with the connecting frame 8 of the hauling vehicle 18according to the invention.

It is appreciated that a hauling vehicle according to the inventionprincipally can be used for hauling or transporting any kind of trailerwhich has a supporting wheel axle only close to its rear end while itsfront end is designed to be rigidly interconnected with the connectingmeans at the rear end of the hauling vehicle according to the invention.

It is also appreciated that for all the purposes described above thehauling vehicle according to the invention must have a weightdistribution between the front axle and the rear axle which is soadapted relative to the weight of the object to be hauled or transportedthat the front axle with the front wheels of the hauling vehicle islifted up from the support when the vehicle is rigidly interconnectedwith the object to be hauled and the frame of the vehicle is raisedrelative to the rear axle in the manner described above.

However, a vehicle according to the invention can also be used as aconventional fork truck for handling goods in that in the mannerschematically illustrated in FIG. 10 a fork device 26, which can eitherbe stationary or designed as a lifting fork, is affixed to theconnecting frame 8 of the vehicle 18. In this case a counter-weight 27should be mounted on the front portion of the vehicle so that thevehicle does not turn over under influence of the load on the forkdevice 26.

I claim:
 1. A drive vehicle for hauling a movable object, comprising arigid chassis, front wheels normally supporting the front of thechassis, steerable rear wheels beneath the back of the chassis, drivingmeans for the rear wheels, connecting means secured to the rear end ofsaid vehicle chassis to provide a substantially rigid interconnectionbetween said chassis and the front end of a movable object, andvertically elevatable means supporting the chassis from said rearwheels, whereby when said vehicle is connected to said movable objectand said elevatable means are extended vertically the chassis will liftsaid front wheels from the ground when the weight of the movable objectis sufficient to counter-balance the weight of said chassis forward ofthe rear wheels.
 2. A vehicle according to claim 1, wherein the rearwheels are mounted on a rear axle which is turnable about a verticalaxis relative to the vehicle frame for steering the vehicle, and therear wheels are drivable by means of driving motors mounted on the rearaxle.
 3. A vehicle according to claim 2, wherein said driving motors arehydraulic motors.
 4. A vehicle according to claim 1, wherein saidconnecting means comprise a substantially vertical rectangular frameattached to the rear end of the vehicle chassis, and at corners of whichthere are provided connecting elements adapted to cooperate withconnecting elements provided at the corners of a container to be hauled.5. A vehicle according to claim 4, wherein said connecting elements arehydraulically actuated transversely of said chassis.
 6. A vehicleaccording to claim 1 or 2, wherein said connecting means are adapted tobe rigidly interconnected with the front end of the frame of a shortsingle-axled trailer provided with a turntable lifting device forinterconnection with trailers designed for hauling vehicles having aturntable.